Technical Field
The invention relates to an imaging apparatus and an optical system, and particularly relates to a projection apparatus and an illumination system.
Related Art
Along with development of optical technology, light-emitting diodes (LEDs) and laser diodes (LDs) of a solid-state lighting technique are widely used as light sources of projectors, where the LDs provide lights with higher intensity to serve as the light source of the projector compared with that of the LEDs.
To use a high intensity laser beam emitted by the LD to excite a phosphor conversion module is one of common techniques of applying the LD as a light source, and the high intensity laser light is used to excite different phosphors on the phosphor conversion module to obtain excited lights of different colors to serve as the light source of the projector. Today, people have increasing demand on brightness of images projected by the projector, and an LD array with higher intensity is required to emit light with higher intensity. However, when the intensity of the light irradiating the phosphor is too high, a conversion efficiency of the phosphor is accordingly decreased. U.S. Pat. No. 8,573,779 discloses an illumination apparatus, which has a plurality of light sources respectively irradiating different parts of a light integrator. U.S. Patent Publication No. 20120300178 discloses an illumination apparatus and a projective display apparatus.
The information disclosed in this “BACKGROUND” section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Further, the information disclosed in this “BACKGROUND” section does not mean that one or more problems to be solved by one or more embodiments of the invention was acknowledged by a person of ordinary skill in the art.